I got myself film caps similar to my film camera days to serve as enclosures for the 2 switches- 1 for focus and another for the shutter release.
Materials used:
2 - push button switches, normally open
1 - baby plug (similar to those in headphones)
2 meters of 3 wired cable
1 enclosure (up to you)
all I needed to do was assemble the two switches on my chosen casing.
Solder them together in series with ground conector of the jack soldered to one end



the casing I used in my project, freely available and did a wonderful job unnoticeable to most people :)
Imagine the cost savings I got aside from the feeling of accoplishment I have of all my other DIY stuff